1 /*
2  * This file define the irq handler for MSP SLM subsystem interrupts.
3  *
4  * Copyright 2005-2006 PMC-Sierra, Inc, derived from irq_cpu.c
5  * Author: Andrew Hughes, Andrew_Hughes@pmc-sierra.com
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
12 
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel.h>
16 #include <linux/bitops.h>
17 
18 #include <asm/mipsregs.h>
19 #include <asm/system.h>
20 
21 #include <msp_slp_int.h>
22 #include <msp_regs.h>
23 
unmask_msp_slp_irq(struct irq_data * d)24 static inline void unmask_msp_slp_irq(struct irq_data *d)
25 {
26 	unsigned int irq = d->irq;
27 
28 	/* check for PER interrupt range */
29 	if (irq < MSP_PER_INTBASE)
30 		*SLP_INT_MSK_REG |= (1 << (irq - MSP_SLP_INTBASE));
31 	else
32 		*PER_INT_MSK_REG |= (1 << (irq - MSP_PER_INTBASE));
33 }
34 
mask_msp_slp_irq(struct irq_data * d)35 static inline void mask_msp_slp_irq(struct irq_data *d)
36 {
37 	unsigned int irq = d->irq;
38 
39 	/* check for PER interrupt range */
40 	if (irq < MSP_PER_INTBASE)
41 		*SLP_INT_MSK_REG &= ~(1 << (irq - MSP_SLP_INTBASE));
42 	else
43 		*PER_INT_MSK_REG &= ~(1 << (irq - MSP_PER_INTBASE));
44 }
45 
46 /*
47  * While we ack the interrupt interrupts are disabled and thus we don't need
48  * to deal with concurrency issues.  Same for msp_slp_irq_end.
49  */
ack_msp_slp_irq(struct irq_data * d)50 static inline void ack_msp_slp_irq(struct irq_data *d)
51 {
52 	unsigned int irq = d->irq;
53 
54 	/* check for PER interrupt range */
55 	if (irq < MSP_PER_INTBASE)
56 		*SLP_INT_STS_REG = (1 << (irq - MSP_SLP_INTBASE));
57 	else
58 		*PER_INT_STS_REG = (1 << (irq - MSP_PER_INTBASE));
59 }
60 
61 static struct irq_chip msp_slp_irq_controller = {
62 	.name = "MSP_SLP",
63 	.irq_ack = ack_msp_slp_irq,
64 	.irq_mask = mask_msp_slp_irq,
65 	.irq_unmask = unmask_msp_slp_irq,
66 };
67 
msp_slp_irq_init(void)68 void __init msp_slp_irq_init(void)
69 {
70 	int i;
71 
72 	/* Mask/clear interrupts. */
73 	*SLP_INT_MSK_REG = 0x00000000;
74 	*PER_INT_MSK_REG = 0x00000000;
75 	*SLP_INT_STS_REG = 0xFFFFFFFF;
76 	*PER_INT_STS_REG = 0xFFFFFFFF;
77 
78 	/* initialize all the IRQ descriptors */
79 	for (i = MSP_SLP_INTBASE; i < MSP_PER_INTBASE + 32; i++)
80 		irq_set_chip_and_handler(i, &msp_slp_irq_controller,
81 					 handle_level_irq);
82 }
83 
msp_slp_irq_dispatch(void)84 void msp_slp_irq_dispatch(void)
85 {
86 	u32 pending;
87 	int intbase;
88 
89 	intbase = MSP_SLP_INTBASE;
90 	pending = *SLP_INT_STS_REG & *SLP_INT_MSK_REG;
91 
92 	/* check for PER interrupt */
93 	if (pending == (1 << (MSP_INT_PER - MSP_SLP_INTBASE))) {
94 		intbase = MSP_PER_INTBASE;
95 		pending = *PER_INT_STS_REG & *PER_INT_MSK_REG;
96 	}
97 
98 	/* check for spurious interrupt */
99 	if (pending == 0x00000000) {
100 		printk(KERN_ERR "Spurious %s interrupt?\n",
101 			(intbase == MSP_SLP_INTBASE) ? "SLP" : "PER");
102 		return;
103 	}
104 
105 	/* dispatch the irq */
106 	do_IRQ(ffs(pending) + intbase - 1);
107 }
108